SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b92f693605bb34410c2043f740ba959f55cbce38ad03f1edf1fa3d41d7924d87' 
  AND token = 'iAJ9zimcPPBXK5a0PLeMUAAPrUvnXoxRbmEkSk6Bqms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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