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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83f5424f5703fbc855e0549d16df6d09a31c30dc1f567fe1c9cbf9c06ab371c3' 
  AND token = 'XZFmJ3fRwxTmFWMZbLOoLyPBRb4v4mIVDbkTb4Wl480=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}