SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89c0c90c8c3a8ba083058cebec430232e8c80299e9c8bbbc212556ffe4d5d3ae' 
  AND token = 'Rxxgd/a7x6IRxJlYq3VkG5k6JNAY/bJmkmzVBEPdncA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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