SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9468d2104daaab918cd460c74f28d73ae648d1ad13b57a22e8a2fb22f09eca7f' 
  AND token = '5uUzKgtUlXCuN5amwIAanFj1BFTGLzCGrh7Ppw0LfQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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