SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08e7f230278f9e704a860c2284134d41e1068491efffa20f018a316da87af403' 
  AND token = 'IHBmFxN2nndXkOno2GsnzOqonnbB4MnSprPF5DSFYqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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