SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc2a0f2f0b3fd29da545cf8171022d4913c5a48f7360883bcd79d5334cb6ab7a' 
  AND token = '0hFrdrvKQX1a+wqRJAYTQsxshSnSksq31HLZmZahjWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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