SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '440931b79ce33910a9f32a68a853193e52e7b54445bec80abd6845fca73c702a' 
  AND token = 'Tl/JAxCVD8YKsUBsWbDcWOQdcyQO6YpOHGfkubXju9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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