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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c94dbac9306393c8dac066749186f0e2dab53de2d9fc80f550564ba456a0233' 
  AND token = '0vYm929wgU6LYD5Trcel3IyfOzKgcQyyHv9b22gRTbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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