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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a936d9a731db05d4cc3d5d867f4564ac850f22a2ee24ad9c700bb10ea149d38' 
  AND token = 'NBYnL9BiFbWmFrU5lPG15Jpvdj09/pZS0UyuJhmO724=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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