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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df7e7552f6b1b118246db687e9f6787a149a7630a9fd1c17ff286875575d6163' 
  AND token = '+uLUiyzOe04CALT15ywZine7ysB8QKLJVnJr9/rFIIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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