SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69d6bf6f640e558964f4c2da379c37e5d8e16385b26022f832353f3f482da9e5' 
  AND token = 'VtAcMofayU63J1EK+BtXLDNjMu/P6lsm+ehuRdlHD7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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