SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfdfcde06bf5d3b1ff6fb94768f5d0bc435660da19bcafb63f7149de78409b2e' 
  AND token = 'VJfCgXzGsImwXQGBrEvdjRveQ6te1VMJ2MvODcEvvCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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