SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50b74f98adbbf6004ac337f046cc182867965fee6ad198a3951189d8ec4a5f13' 
  AND token = 'qpsSPZf21V/PLXndeYShv5J+0gpKSJtsR/bdDBOTP4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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