SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37e0daf6c1f872bea828da8de99754613471ff17c1287cdc5e6fa0636b930911' 
  AND token = 'UvAIUsqzWfhmzLSaPRHn56/4TY+G5HPKyT0eUAP8ocA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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