SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b855674d24136ada3ce38c09b97980c4dd3147b1a2e4eb1bd0e42d44d33c14fc' 
  AND token = 'bqLAgv2A/BC833rLrvoy43VEBvLrHeQmDat6XFXFsHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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