SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '368fbe3ebe737c2085b45106dbb8e08c76f5ba7a74b2d1f532e18b7cbd282995' 
  AND token = 'uuuKQJxvjfyFqVZVI/LRSB1yfQsfAwFqDFvDb35vJes=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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