SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab78656529367b710e7c45b8695b4023c48a05a272ce09253a5d960015e79831' 
  AND token = 'ibf0Ew6DEwkwvhVdHCSYp7wHLcBG5lIHavmLEHNZ7UA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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