SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcceb98f56da827e8dd9441d59f0aaa5f948212a38970271e5fdeb2c9dda624a' 
  AND token = 'nK1ief5Wg3hO/AaDcK9CIOOx+mM6zOuuBuVmkqI6Ng8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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