SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0e6b214e156031e03306097c1dbe642b00c9088125595aefd13d7438b3c94aa' 
  AND token = '1QiTmQ4aJl+jCkdiDxUVmq8RTtudgK8kBwYNYAXCdhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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