SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edf5cd1d8eb2e77fee6f75c40598e6a8075d4d5b63825ea25c97c27b2b8dd83e' 
  AND token = 'RCcCQzHKSLq4KKzsWp5u9Bw5yDCeg/3+V+Gnjy4i17Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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