SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd12df0d0e44c9784decb101f109f7df449a26266bf70ae09c3825bb6e2c74353' 
  AND token = 'ZPF8V5gCv8ZZBmMCL/+c00/YbmTKoJdA9fJT6YZDhLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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