SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2a1915715b1a77e85b59ebf90b433e646c3079d3149c4109daed99da778e7dfa' 
  AND token = '9njxf5JSKQLgyk5cBH27z4YZDIMHW+5JB5BBGDASNno=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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