SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e8ec2b073d835c94bb09b119e937525b027032e74c0b798007efffbf32f32ff' 
  AND token = 'fbqb9jJSXPpignzdVT3IrK4pNeeaftm0kBNifoStR44=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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