SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1bc3b27b812dcce9f6316a9e2d052509d8f1bc6d65b90707417429b70cf12d' 
  AND token = 'h+lvHfEOBtivL3ZDxdUaKLTGLfMnxJ15wNhXBwqMzJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00147

JSON explain

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