SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '22be717a6c5e8f79a846a0aefad39bf8262a5f2d9af1e93374254da986ab067f' 
  AND token = 'nX2C5GsVWskQPOqbJnDMjYuO3BlTwmpLtiYLPLB1ZbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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