SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78161f8a2e64ba05c1b4d19d8fa5609d14c91f3bc4183d4b94e83022f8226113' 
  AND token = 'mkIfU/D0EwN3UKB8XPGCqex7y+WwMkAOmTNyCzGea+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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