SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a4aafc98f371218f9914e75c3a3cbf269b855a5751fed5274a89e7bc140877f' 
  AND token = 'v1vLpsLb1XuA0YPCLt6D/kh16DUx14pJOVVpqClRju4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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