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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53d4ff1bb37a75ab12142b421c04e140c38157a7f0e8caa9ee7dc437afa8a138' 
  AND token = 'vFqwwDXqRTy1lTxhR1EuG7LK+aLeXxlkWckD3oRq9qA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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