SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a75a4856bc1f5f91b34b4a974c30b30fcf075ea93633d232cf40ecab785523e4' 
  AND token = 'ifdbRJMw6rIqAa/MIy1leEp9cx/xnri7/N4uT8n0UnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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