SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b44109dd4a7b19739b045191e31185ae1046b285e09bd4024605e5e4583ecf34' 
  AND token = '2epexWjYKD4PmmPwv+DZDL+rRQKqpPpXOgQR0sK3Ess=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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