SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3bd7b8e8c3137864e15aabbc94ff578477bd012e29b2c0b0a77998be4f7b732b' 
  AND token = 'hN4KT9A26XSYQowGyYCVZusqye2qUVepcv71zkr/Kdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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