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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a9e2012ddfd1f5dce63179a376ceb94cfa38d447ff746ca874e46d6e755ee218' 
  AND token = '3Q7DDQfTV5AALjjagW4j/hrcaoYbzTg/DPp1Ssq/1Fs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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