SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '533143bc0bf6a51fdb7d045e98f3088d9b89ce69279668e6ad15321eaddfe1cf' 
  AND token = 'ZpvgcPlEL9SE3qq+uzbZemR1zELLNRWlR4cAOQTnP48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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