SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c713c34d476a1c593520ace47e4b64405e937e614a61230bdd7b8bb69d44f8e0' 
  AND token = 'M1i1G2efsJrbjXO1xUuTPXf99KJekkRSCtIwIXFjc6A=' 
  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"
    }
  }
}