SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a4c414c04fcd735021b39d696c99d2856b591961bb7c623a8e2d5c530bfa874' 
  AND token = 'otpPpnlwxpRzfxxJiiE5287n/P3T7wMl2ZHKivO+YR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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