SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78b85e2fdacb18866268d6d04518ab0c281c57719d9e458f5b9f03e79e06d945' 
  AND token = 'ofYKqHDKjcCJC7dMmiuqvGi35+xClHPi0ytGeIGTKRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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