SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f319db1aee1f21d9651e537d734cce5d709a787a6841e9245aa4e6a63288e28' 
  AND token = 'y2rNGrYGLN9jc9Xel8gSyaZuDOOBju653xemBc+LldQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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