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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cb0ced1c3b3abf5f2a03879d13f59edd5942180fdf0f05ad63e6b8d61ee08ec7' 
  AND token = 'xnzLDd+ca23dB/KH97cuMRSh5SbY/fsXdOpx+4O28J4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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