SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a4bc12c8df1d73b22910a2bfbb4390d22d05cbf5fc3f0d437f88035648d6e5a' 
  AND token = 'FYmFKVd3oP/t6LIeOP663Dcewe/LZJJrGQMHJWZ0/Fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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