SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17c8688adbf32d4bf26b77d2719565944b8d5f4570400e63022adf3feb66b88c' 
  AND token = 'C2tRn6YDuK6Uoj7XpSXhdL+xiGKKT1ax3iXNY1ZGhvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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