SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c0c2ade53f84d5f50fc452b0322250a0d041b37f341b2b36a8cb432904b61e6' 
  AND token = 'gPsJYjuGsJ1LxSYtKubfjwgOym4+1Q4cdURVqFiyQhM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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