SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28db1d8cb6c88d6cdfeadfd7c19c0900971c0d597e3b01c358322c14ec7f0886' 
  AND token = 'bqmrY0ooloptoPv9FJGb7h98dEVzsXVZAvH+TE2FKLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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