SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba304a9be29a276e091c69bede38a5e69266d888d66d99961451916fe5ecdfca' 
  AND token = 'hq/2uCxGdCiWQ3hTOuBVgjgERR0sLYIB7fjyJDH17BU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}