SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c74513b2f5a41c10aeb70f9aa644e3d31b3a4ea300ad8c47194e173dd7875ed' 
  AND token = 'BMcV6sREekkEfG+OcOPj4Hwyf3nGwXRHRZB99Nq2AvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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