SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7efee97fb66a1884937fa2176d8a835473436b4142304029b7a0f23593c42f3a' 
  AND token = 'ifiUA5IYlqvYMsjYcso5s/NLbjzt0gJGTEKwIWdkr1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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