SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37e4ac5e134a84f2317da3335f6400133ad9da98efe26dc3ca462bdbd751fdf9' 
  AND token = 'hSAb8+jYU7IcizHdcngLA9WqlU0xzO5teshUMO6iM9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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