SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ed3994c7be90b3f28a466496f77fd87c6f0ec1a20be3508129b863056c8b70b' 
  AND token = 'o/xeE3tlNjrXTT3VDKIXpltHkjQzLO09BrA3bPiTcFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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