SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff31abce9906f29a9332efd9e16815aca59ab436f74a89a446b838f278d2379d' 
  AND token = 'zWGu2Yo+14lmJdEDUN6gfIIkXiFBXAASgoXMGQAR4+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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