SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '44b9384f2a8474e4a7e14de86b482208fbfb6d99136bc2e534abaa24d3540828' 
  AND token = 'JWtUfFvIV1H1uUP+JIhBKd4W9RrgFFwbgNTWzFmNLAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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