SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '597d222daf82ec8e5a77bc456620c203bacbad2bb886d3b6781a2ec3628fc19c' 
  AND token = 'KcAXIzx6kCkoozaTZhufvj1ByXMj7hwrYHmdGSMfbpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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