SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fc414c93db7cc3f19c93c17321b674836dcc8c05bef38114a49bd7e210615eb' 
  AND token = '+LwLBW/EdcAJgkaikI2XLo1dHxXa03hVkNLx4FXvZBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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