SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd7df4d860a8b12937d6dae9f6af787250f4f2a911283e12db11725fa00ab297' 
  AND token = 'zeYJAHOGjqO4o/dVSs06Iq0K1+BYpPdHX6UbWJIqIaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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