SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b59457fee27dfb4b09d87bc06a0dc25795de75537ac0fc7512733c5775d34511' 
  AND token = '5XElxgv5HNJ6meRyzpATT5/jJTSA3TA6zhZsipFzEc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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