SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc0694395cdbe14984d697bb4311f2633e336d95ce3fe28c4ad23740a7aa1043' 
  AND token = 'TuM4iPl4YC70zSY7kRRywTNLnN2EWAVf0R5JFaPOjkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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