SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1765af4600081813d22dd17df50222f2b394b374c38d9d88b3827fdb6f30009' 
  AND token = 'dxS7yBvRW6rRlUylIi41GrC+v2xEhwCQOHie/mSNTdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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