SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6c42eba22d2ab0d11597a90b9463b116c7fbb78dd8a8a19d85ee512bbcc80ce' 
  AND token = 'SIa2NK2Shf5oK7mF1kJI2cST8mK5Zw+22ge5eUPr7ys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}