SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ffe41c99b58fa901afab1d030e3a796ed0cad37eb35eaee99419a3cf278deb7' 
  AND token = 'NQNYKiX7pY4AJAquMnHVygWLjkX92E0abpGc8yuTZV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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