SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edb4d535c35638efe20c55e298cb4dc2d73687310c0a3fdb738be4eea8cb604a' 
  AND token = 'd/L+cJcyLwEVTwaV0SnUeYqeJOjSlOcg5UWSauKUuv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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