SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fde0079ee5936f64906f2a875047a71f9cd906fab3dcd8291c592bacacaf3fa2' 
  AND token = 'kJ3iv2VVVEaMnsiPRVmWRgXrXqznXAJzrXnMTlKi6+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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