SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6760a4e92bb80e7f8aba1f6d8475389a2e0e48817e62b735de272a515acbf00a' 
  AND token = 'hFLehVFjOowA2ffvgKBIoUQq/0xh3BVYYYhC6OPZG2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}