SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b2b1010f5c5f954f3ef4d2a12ba7cc62928ea51a17c2ba947b35a3baad6a373' 
  AND token = '+GoejXOZudwVv+yw45vhd88BJXJ1mCpvOi+oHGYzJI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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