SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18e30d2d2b72c386bfdd1ad84dfe7502b0de04a0a8430325fb01ba0f47f6d8cc' 
  AND token = 'vOZXk0vKr/JRMIMTRLiGfD/nne4zlaZOM6wYtyOFYSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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