SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ffcc18e8a908d5e95ea94fa7456b48370b04520cd7167a8ff41fbb2d8b7c75a7' 
  AND token = 'Yy0trW9QYcR0+zDepMzNNUtGuYMRCiV5LGPv7LRNebg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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