SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bfb2f61669fb83836f47d5b46a94d19e1821fa3ee7686bbc2d3e205709da5cf' 
  AND token = 'aiUAra9oqyTGb4U7Fk6P/HJZEdRxftuWcShGCY9dp6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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