SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd691639fde49ffbd86d0b4bd31a2258b034de058f479ceebfa699b678a0dd662' 
  AND token = 'VpwlQqZzQEizonb8vxs8j0ZCZpzXWkziIBNH+tBFqqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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