SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd7d6c793b107237662cce7cde9789b290dff42cd9b8d4bf8dc2299fd143b95bd' 
  AND token = 'Z+EVjM0ZZl0UhbE5MSefyPihVJJf3w3Vets34yjK84o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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