SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7f88683f8566c0939ff03e070741377a5ea5246834b1902fa995bdf0d7935d5' 
  AND token = 'o652/La7oStKw6NiVAbfRGGM75KWrc0C0LWobLJgmrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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