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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e5fdbdcadc2d4fcc08996436e18b78406a85c32848f0cfae65b8943db57bd5b5' 
  AND token = 'ltEQ6AIrE9v+XmPWPzrE3aQNiSv5yFg96OZfVFRjHcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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