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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8947bde0f09b055aed31c684f4d4ee967e1023af9432693c3a4284b2ec1fa6f' 
  AND token = 'f+yPyFCtFBRnISmjdC9PC7lRghHZ7ffLLoP9rPjpO8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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