SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '243e7b1bad69b0e90e0f86c150890956e44b10ee86417df1eb3e939a66a0cbc4' 
  AND token = 'pvCo0rhcwiajoqogupz90Lxt1uI1glJaNTrRtkmPX6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}