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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '500a0f4ac4f70faa0b60b5ec3173ad2b64c6bd201781599b6fd40431e7d9b5eb' 
  AND token = 'uvawGO5U4GB5Sknwsx/t1r5+Da/+6Re5a4YEIg4EOFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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