SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9d6dbfffca0530c99039a12f599da8f39cadb842a2ba9144be80d13cc8ad080' 
  AND token = 'r5QlJGdRhHjvlpjZW+7b4C+kcyPH9tyfzFeLy9Gflrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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