SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8f10c1470529775804c7e68590a8472db8c1d3ab7c28eea012946ae29dc372df' 
  AND token = 'UgqxZG697Cu/G+Y5bX9KCYng3rrOCYjjr1E/+IiloPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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