SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a179046d679d075f640ab91a179a370074293b3d4b6295776dfbcca0d06b28fc' 
  AND token = 'RocjpvGytM1kJPFCeSqQwURBL8O+wgxvRE2lIzX3qxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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