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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5c6f73b25feecf810f083164161f544b038fd650436cb0a1ba7efe71cd218517' 
  AND token = 'p/he2e0dxDp/PiySW80hxo0sm0fwAdZDyDawhGSAxuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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