SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd74759a2bf61ccb98a13a543d08b5476aad65d266e855efcf61dc79bba8671da' 
  AND token = '7iN2Kmh7z2Vw3WKV6cImu9IIuENRtJ3iJEeJ2Lo5d9k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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