SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36274e88a9901e7fa828bd9d8d2e11f761237f1b12b854267d4e29e21eacbe0c' 
  AND token = 'p62eP95eqfYtPXNRcYhTmcB8ik677vhzAAazwIdAluQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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