SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2448a67f7c2fc593d08845e97dccaf0a409b0f2a15eeaeb3b9ed264c43eb2aab' 
  AND token = 'hYzzJrBYnM7tXgSedN4pNi2V63tfJi/0uPFeIhtb/4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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