SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c141ec78e883e9763dc36237ff75b70926c30131b60dcb51b20d51b3907ccbb' 
  AND token = '+zNIa30O337MmYy6w+srH2NGg43jS9CukMN6mjZL5TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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