SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d6058cd8452f4d6d70d3d2a51461db20aa651a1e4c0c53d2f18f9ec28204772' 
  AND token = '+Wh0xzELYuO2zTGCqeLUPmjU7ojbnma/+WCUBHLQBJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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